*** Publication

These are the replication files for the following publication:

Vink, M., L. Van der Baaren and D. Reichel (2025). A global panel database of dyadic dual citizenship acceptance. International Migration Review. https://doi.org/10.1177/01979183241305388.

Replication files at: https://doi.org/10.7910/DVN/GGEKEY. 

*** Abstract

Dual citizenship provides access to secure legal status and rights in more than one country for an unprecedented number of migrants and their descendants worldwide. While this double allegiance requires matching legal regulations between two states, existing studies of dual citizenship typically focus on migrant origin or destination perspectives. To explore this phenomenon’s dyadic nature, we introduce a procedure that leverages existing monadic data on two distinct types of dual citizenship restrictions: origin country restrictions on the loss of citizenship by citizens naturalizing abroad and destination country restrictions requiring foreigners acquiring citizenship in a country to renounce any other citizenship. We add novel data on dyad-specific regulations in place in nearly 13 thousand country-country-year combinations. This results in a global panel dataset of the regulation of dual citizenship in 1.8 million directed dyad-year observations in place between 201 states back to 1960. An open access replication script allows reproducing and updating the dyadic dataset with new available data. We identify regulatory trends and present estimates of the number and proportion of global migrants affected by changing policy constellations and variation in acceptance across political regimes. We show that migrants are more likely to acquire destination country citizenship and thus achieve democratic representation in constellations where they can maintain a legal link with their origin country.

*** Technical requirements

The replication files require the statistical software R to run (version 4.4.1 or higher, available here: https://www.r-project.org). Analyses performed in RStudio version 2024.04.2+764.

*** Instructions

1. To run the replication, create a new project directory in RStudio and copy all files in your working directory.

Then go through the following four steps:

2. Run the code 'dc_dataprep.R'

Running this code reconstructs the monadic and dyadic data files used in this paper based on version v2.0 of the GLOBALCIT Citizenship Law Dataset ('data_v2.0_country-year.csv'), combined with a dyadic correction datafile ('dc_dy_corr.xlsx').

This produces the files 'GcDDCAD_v1.0_monadic.csv' (monadic data) and 'GcDDCAD_v1.0_dyadic.csv' (GLOBALCIT Dyadic Dual Citizenship Acceptance Dataset (v1.0) - Dyadic data).

3. Run the code 'data_trend_description.R'

Replication file to reproduce all descriptive plots and tables included in the paper.

Tables and figures will be stored in the project directory.

4. Run the code 'dc_natrates_dataprep.R'.

Running this code produces the analysis dataset that is the basis for the motivating example in the paper where we analyse the association between dyadic dual citizenship acceptance and naturalisation rates, using data from Eurostat.

This produces the file 'dc_natrates_dyadic_data_[date].csv'.

Our analyses were done based on a dataset with data from Eurostat and the WDI from 23 June 2023. Note that downloading data on a different date (when running dc_natrates_dataprep.R) may result in slight differences in number of observations due to changing data availability from Eurostat and WDI. For exact replication of our analyses, use the replication file 'dc_natrates_dyadic_data_2023-06-23.csv'.


5. Run the code 'dc_natrates_analysis.R'.

Running this code produces the output of the analysis from the motivating application in the paper. Note that not all the numbers reported in the R script and the paper will be reproduced exactly due to the use of random sampling processes in the analysis.

Note that running the Bayesian models may take several hours per model. We provide the files 'model1a.rds' and 'model1b.rds' for replication. To reproduce these files yourself, remove ### in the code at lines 277-311 and 318-352. Note that not all numbers will be reproduced exactly due to the use of random sampling processes at this point in the analysis.

We also provide the output file from the betaregression ('m2a_beta_fixed_full.rds'). See lines 408-410.

Tables and figures will be stored in the project directory.

*** Contact

For questions, contact the corresponding author Maarten Vink at maarten.vink@eui.eu

Date: 20/01/2025

